The present disclosure relates to a fixing device fixing a toner image onto a sheet and an image forming apparatus including the fixing device.
Conventionally, an electrographic image forming apparatus, such as a printer or a copying machine, forms a toner image onto a surface of a sheet, and then, heats and pressures the sheet and the toner image by a fixing device, thereby fixing the toner image onto the sheet.
Recently, because requests of energy saving and shortening of a warm-up time are increased, reduction of a heat capacity of the fixing device is actively considered. As a concrete manner actualizing the reduction of the heat capacity of the fixing device, for example, there is a “slide belt manner”. The fixing device with the slide belt manner includes a fixing belt, a pressuring member configured to come into pressure contact with the fixing belt so as to form a fixing nip and a pressing member configured to press the fixing belt to a side of the pressuring member.
For example, there is a fixing device including a fixing belt, a pressuring member configured to come into pressure contact with the fixing belt so as to form a fixing nip, a pressing member configured to press the fixing belt to a side of the pressuring member and a sheet member disposed between the fixing belt and the pressing member. In the fixing device having such a configuration, a lubricant may be applied to an inner circumference face of the fixing belt.
In the fixing device having the above configuration, an upstream side end part of the sheet member in the conveying direction of sheets may be fixed to the pressing member. According to such a configuration, when a sheet jammed in the fixing nip is pulled from the upstream side in the conveying direction of sheets, the sheet member is pulled together with the fixing belt, and the sheet member is likely to be detached from between the fixing belt and the pressing member. According to this, there is a concern that abrasion of the fixing belt is encouraged, and an operating life of the fixing device shortens.
Further, in the fixing device having the above configuration, the lubricant applied to the inner circumference face of the fixing belt is likely to drip on a member (e.g. a pressing member) disposed inside of the fixing belt from the inner circumference face of the fixing belt during rotation of the fixing belt. When such a situation occurs, the amount of the lubricant held at the inner circumference face of the fixing belt decreases, and there is a concern that abrasion of the fixing belt and the sheet member is encouraged and the operating life of the fixing device shortens.